Quantitative prediction of elongation deformation and shape relaxation of a red blood cell under tensile and shear stresses

Abstract

The characteristic time of stress relaxation is a key viscoelastic property of cell membrane that controls time-dependent processes such as shape recovery. Although many experimental studies have been devoted to the measurement of characteristic relaxation time, considerable uncertainty still stands because existing methods rely on different experimental designs and analyses. Here, we present a mesoscopic computational study to investigate the elastic deformation and relaxation characteristics of an isolated red blood cell (RBC) under both tensile and shear stresses. We examine the elastic response and relaxation behavior of the RBC under static tensile stretching and dynamic shear stress. When the cell deformation index responding fluid shear stress is equivalent to the one responding external tensile stretching, we find that the characteristic relaxation time for the RBC in planar flows is longer than that for the RBC under tensile stretching. We also subject the RBC to confined tube/channel flows to probe the effect of geometric confinement on its elastic deformation and relaxation dynamics. Our simulations show that the computed characteristic relaxation time is further increased when compared to those obtained under tensile stretching or planar flows, indicating that the confinement would slow down the cell relaxation process, especially under strong confinement conditions. These findings may facilitate a better understanding of variable relaxation time observed in different experiments.

Dynamic response of red blood cells in health and disease

“…In a recent numerical study, Wu et al point out that strong confinement in tube/channel flows slows cell recovery. 52 It is also presumed that surface area by volume ratio, cytoplasmic viscosity and surface alteration of the cytoskeletal network of the membrane play a pivotal role in the cell's deformational response. 28–30,53…”

“…In a recent numerical study, Wu et al point out that strong confinement in tube/channel flows slows cell recovery. 52 It is also presumed that surface area by volume ratio, cytoplasmic viscosity and surface alteration of the cytoskeletal network of the membrane play a pivotal role in the cell's deformational response. [28][29][30]53 To investigate these aspects of cell behaviour, we subjected the membrane ends of the cell to an extreme tensile creep load of 200 pN for a duration of a few seconds and removed the applied load to observe cell relaxation for healthy, type 2 diabetic and malaria-infected cells considered earlier, along with a diverse class of other pathological cells attributed with different constitutive as well as geometric properties as compared to the healthy red blood cell.…”

Mechanism and Effects of Cellular Creep in a Microfluidic Filter

“…Compared with gels of similar softness, cells are much more viscous, which has been quantitatively observed in previous studies . It has been widely demonstrated that cell mechanics can potentially be used to detect the state of a cell in biomedical applications. , As an example, a recent study showed that the mechanics of cancer cells depend on the stiffness of the growing substrate, and they are significantly softer than normal cells on Petri dish . Additionally, the mechanics of different viscous cells will result in various dynamic performances in microfluidic applications. − The transport of flowing cells into the confined microscale structure will induce clogging and trapping, which is related to the surround fluid dynamics and soft matter characteristics of the cell .…”

“…13 It has been widely demonstrated that cell mechanics can potentially be used to detect the state of a cell in biomedical applications. 14,15 As an example, a recent study showed that the mechanics of cancer cells depend on the stiffness of the growing substrate, 16 and they are significantly softer than normal cells on Petri dish. 17 Additionally, the mechanics of different viscous cells will result in various dynamic performances in microfluidic applications.…”

Recent Advances in Computational Modeling of Biomechanics and Biorheology of Red Blood Cells in Diabetes

“…While in the particle-based methods, such as dissipative particle dynamics (DPD), blood cell models are constructed using DPD particles and thus are naturally assimilated with the background flow, continuum-based RBC models often implemented a boundary integral algorithm or the immersed boundary method (IBM) to couple RBC models with the background flow, which are solved using different solvers, including the finite volume method, the finite element method and the lattice Boltzmann method [ 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 ]. Motivated by experimental studies, recent progress in computational modeling has enabled simulations of fluid dynamics and cell aggregation dynamics under physiological and pathological states [ 10 , 27 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 ], which has provided insight into the pathogenesis of the disease as well as facilitated the development of therapeutic treatments [ 51 , 52 ]. For example, RBC models developed using DPD are widely applied to simulate the deformation and aggregation of healthy RBC doublets [ 42 ] together with their effects on the blood cell dynamics in stenosed microvessels [ 43 ].…”